Adjustable snap gauge



March 20, 1951 F. A. BARR ADJUSTABLE SNAP GAUGE Filed June 7, 1946 INVENTOR. FQ/V/ A A/Q) ATTCI RN EYB Patented Mar. 20, 1951 UNITED STATES PATENT OFFICE ADJUSTABLE SNAP GAUGE 1 Francis A. Barr, Laurelton, N. Y.

Application June 7, 1946, Serial No. 675,056

This invention relates to a Vernier gage and it is one object to provide a gage by means of which micrometer measurements may be'taken, the gage having arms shiftable to adjusted positions and provided with blocks or buttons for engagingpwork straddled by the -gage when the gage is in use. f

Another object of the invention is to provide a gage having a iirst arm and a pair of second and third arms shiftable towards and away from the first arm, the second arm being longer than the third arm and so'mounted that the second and third arms may be adjusted independent ofr each other.

A Another object of the invention is to provide a gage having first, second and third arms with the second and third arms carrying blocks, on: constituting a go block or button and the other constituting a no go button.

Another object of the invention is to provide a gage wherein the rst, second and third arms have Shanks shiftable longitudinally of each other to adjusted positions, the shanks of the second and third arms being provided with scale marks and the shank of the rst arm being also provided with scales companion to the scales of the second and third arms, and allowing very 'accurate measurements to be obtained.

Another object of the invention is to provide a gage consisting of elements formed of hard metal and very simple in construction.

The invention is illustrated in the accompanying drawings wherein:

Figure 1 is a side view of the improved gage;

Figure 2 is a top plan view thereof;

Figure 3 is a rear View of the gage;

Figure 4 is a fragmentary sectional view taken along line 4-4 of Figure 1;

Figure 5 is a perspective view of a block or button carried by the second arm of the gage.

This improved gage is substantially C-shaped when viewed from a side and has a rst arm I and second and third arms 2 and 3. A shank 4 extends from the rear or inner end of the iirst arm and has opposite side faces formed with longitudinally extending grooves or tracks 5 which are undercut along their side edges, as shown in Figures 2 and 4. Shanks and 'I extend from the rear ends of the second and third arms and are formed with ribs and 9 which fit into the undercut side edge portions of the grooves or tracks 5 to allow sliding adustment of the Shanks 6 and 'I longitudinally of the shank 4 but prevent lateral displacement of the same from the grooves. Flanges IIJ project laterally 1 claim. (e1. 3s-16s) from the shank 4 along rear side edges of the grooves or tracks =5 and these flanges carry plates IIxwhich are secured by screws I2 and projectV partially across the outer side faces of the shanks 6 and l. Screws I3 which are screwed into sockets formed inthe shank 4 pass through slotsv I4 formed longitudinally of the shanks 6 andV I and when the screws are tightened their heads bear against the outer sidefaces of the Shanks and I and iirmly hold the second and third arms in adjusted positions. Each shank 6 and 'I is provided along its outer side face with a scale I5 which in the present illustration is four inches long and divided into inches and hundredths of an inch andeach plate II is also provided withA ascale I6 divided into thousandths of an inch, it being understood that the scales may be marked to provide any selected fractions of an inch.

Rear end portions of the second and third arms are outwardly olset so that their shanks may extend along opposite sides of the shank 4 of the first arm and on the front ends of the second and third arms are formed heads II and I8 which are of such thickness that the head II has its side face flush with the outer side face of the third arm 3 and the head I8 bears against the inner side face of the second arm 2, as shown in Figure 2. Grooves I9 and 20 are formed in the heads of the second and third arms and into these grooves are tted blocks or buttons 2I and '22. The go button 2| and the no go button 2'2 are of duplicate construction and each is formed with a longitudinally extending slot 23 and a longitudinally extending recess 24 to accommodate the heads of screws 25l which pass through the slots 23 and into sockets formed in the heads l1 and I8. When the screws 25 are tightened the buttons will be held in adjusted positions and when the screws are loosened the buttons may be slid longitudinally to positions in which they project from under faces of the second and third arms desired distances. Set screws 26 are threaded through openings 21 formed vertically through the forward ends of the second and third arms and by turning these screws they may be brought into engagement with upper ends of the blocks or buttons and limit upward movement of the blocks. The'front end portion of the first arm is formed with a recess 28 into which fits a block or button 29 formed with threaded sockets 30 to receive screws 3| which are passed upwardly through the arm and serve to hold the block 29 in place.

When the gage is in use the second and third arms are shifted with relation to the first arm until a predetermined reading is obtained by the companion scales and the screws I3 tightened. The go and "no go buttons are also set to cause button 2| to have its lower end spaced upwardly from the plane of the lower end of button 22 a predetermined distance and the gage disposed in straddling relation to the object to be measured as shown in Figure 1. Adjustment of the buttons 2| and 22 provides a predetermined tolerance.

Having thus described the invention what is claimed is:

A gage comprising an L-shaped first arm having an upwardly extending shank at one end thereof, second and third L-shaped arms each having a depending shank at one end thereof, the shanks of the second and third arms being disposed at opposite sides of the shank of the first arm and formed with longitudinally extending slots,`the shank of the vfirst arm having its opposed side 'faces formed with 'undercut grooves and the shanks of the second and third arms being slidably received in the 'grooves and having ribs along their side edges 'engaged `in the undercut portions of the grooves to prevent lateral displacement of the shanks of 'the second and third arms 'from the grooves, screws passed through the slots and engaged in threaded sockets formed in the shank of the rst arm and when tightened gripping the shanks of the second and third arms to hold the second and third arms in adjusted positions, flanges projecting outwardly along rear edges of the grooves, plates carried by said flanges and overlapping the side faces of the shanks of the lsecond and 36 third arms, the plates and the shanks of the second and third arms having companion scales marked thereon, a block mounted in a recess formed in the end of the rst arm remote from the shank, the second and third arms having their ends remote from their respective shanks formed with heads having recesses leading from their inner edge faces," blocks fitting in the recesses of the second and third arms and shiftable longitudinally therein and formed with longitudinally extending recesses and slots, and screws passing through the slots of the blocks and screwed into sockets in the second and third arms with their heads engaged in the recesses and gripping the blocks to hold them in set `positions when tightened.

FRANCIS A. BARR.

REFERENCES CITED The following references are o'f .record in .the file of this patent:

UNITED STATES PATENTS Number Name Date 1,057,954 'Foulon Apr. 1, 1913 1,088,175 Phillips Feb. 24, 1914 1,107,276 Farrington Aug. `18, "1914 1,138,438 Bailey May 4, 1915 1,650,704 Gaa Nov. 29,1927 1,899,253 Aldeborgh Feb. 28, 1933 -IEORETIGN PATENTS Number Country -Date 462,109 Germany July `'4, 1928 

